Fibroblastic connective tissue naevus pathology

Fibroblastic connective tissuenaevus typically presents in the first decade of life, often as a poorly defined plaque-like cutaneous thickening arising most commonly on the trunk and head/neck of girls.

Histology of fibroblastic connective tissuenaevus

Fibroblastic connective tissuenaevus is situated primarily in the reticular dermis, and often shows extension into the superficial subcutis (figures 1, 2). There may be a mild papillomatousepidermis. The lesional cells are bland spindle-shaped fibroblastic/myofibroblastic cells with indistinct pale eosinophilic cytoplasm and tapering nuclei, with no significant cytologic atypia or pleomorphism (figures 3, 4). These cells form short fascicles with no particular orientation to the overlying epidermis and are associated with a loose stroma composed of mainly delicate or wispy collagen bundles (figures 3, 4).